Nuclear Theory·nucl-th

Wednesday·March 13, 2024

12 papers—2 primary·10 cross-listed

03
Simulating Meson Scattering on Spin Quantum Simulators
Elizabeth R. Bennewitz🇺🇸 · Brayden Ware🇺🇸 · Alexander Schuckert🇺🇸 · Alessio Lerose🇨🇭 · Federica M. Surace🇺🇸 · Ron Belyansky🇺🇸 · William Morong🇺🇸 · De Luo🇺🇸 · Arinjoy De🇺🇸 · Kate S. Collins🇺🇸 · Or Katz🇺🇸 · Christopher Monroe🇺🇸 · Zohreh Davoudi🇺🇸 · Alexey V. Gorshkov🇺🇸
Studying high-energy collisions of composite particles, such as hadrons and nuclei, is an outstanding goal for quantum simulators. However, preparation of hadronic wave packets has posed a significant challenge, due to the complexity of hadrons and the precise structure of wave packets. This has limited demonstrations of hadron scattering on quantum simulators to date. Observations of confinement and composite excitations in quantum spin systems have opened up the possibility to explore scattering dynamics in spin models. In this article, we develop two methods to create entangled spin states corresponding to wave packets of composite particles in analog quantum simulators of Ising spin Hamiltonians. One wave-packet preparation method uses the blockade effect enabled by beyond-nearest-neighbor Ising spin interactions. The other method utilizes a quantum-bus-mediated exchange, such as the native spin-phonon coupling in trapped-ion arrays. With a focus on trapped-ion simulators, we numerically benchmark both methods and show that high-fidelity wave packets can be achieved in near-term experiments. We numerically study scattering of wave packets for experimentally realizable parameters in the Ising model and find inelastic-scattering regimes, corresponding to particle production in the scattering event, with prominent and distinct experimental signals. Our proposal, therefore, demonstrates the potential of observing inelastic scattering in near-term quantum simulators.
↳ quant-phcond-mat.quant-gashep-phnucl-thQuantum(2025)·43 citations
04
Quenching and flow of charm and bottom quarks via semi-leptonic decay of $D$ and $B$ mesons in Pb+Pb collisions at the LHC
Shu-Qing Li🇨🇳 · Wen-Jing Xing🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳
Heavy flavor particles provide important probes of the microscopic structure and thermodynamic properties of the quark-gluon plasma (QGP) produced in high-energy nucleus-nucleus collisions. We study the energy loss and flow of charm and bottom quarks inside the QGP via the nuclear modification factor ( $R_{AA}$ ) and elliptic flow coefficient ( $v_{2}$ ) of their decayed leptons in heavy-ion collisions at the LHC. The dynamical evolution of the QGP is performed using the (3+1)-dimensional viscous hydrodynamics model CLVisc; the evolution of heavy quarks inside the QGP is simulated with our improved Langevin model that takes into account both collisional and radiative energy loss of heavy quarks; the hadronization of heavy quarks is simulated via our hybrid coalescence-fragmentation model; and the semi-leptonic decay of $D$ and $B$ mesons is simulated via PYTHIA. By using the same spatial diffusion coefficient for charm and bottom quarks, we obtain smaller $R_{AA}$ and larger $v_{2}$ of charm decayed leptons than bottom decayed leptons, indicating stronger energy loss of charm quarks than bottom quarks inside the QGP within our current model setup.
↳ hep-phnucl-exnucl-thCPC(2024)·6 citations
05
Spatially oscillating correlation functions in $(2 + 1)$ -dimensional four-fermion models: The mixing of scalar and vector modes at finite density
Marc Winstel🇩🇪
In this work, we demonstrate that the mixing of scalar and vector condensates produces spatially oscillating, but exponentially damped correlation functions in fermionic theories at finite density and temperature. We find a regime exhibiting this oscillatory behavior in a Gross-Neveu-type model that also features vector interactions within the mean-field approximation. The existence of this regime aligns with expectations based on symmetry arguments, that are also applicable to QCD at finite baryon density. We compute the phase diagram including both homogeneous phases and regions with spatially oscillating, exponentially damped correlation functions at finite temperature and chemical potential for different strengths of the vector coupling. Furthermore, we find that inhomogeneous condensates are disfavored compared to homogeneous ones akin to previous findings without vector interactions. We show that our results are valid for a broad class of $(2 + 1)$ -dimensional models with local four-fermion interactions.
↳ hep-phcond-mat.str-elnucl-thPRD(2024)·11 citations
06
Baryonic Vortex Phase and Magnetic Field Generation in QCD with Isospin and Baryon Chemical Potentials
Zebin Qiu🇯🇵 · Muneto Nitta🇯🇵
We propose a novel baryonic vortex phase in low energy dense QCD with finite baryon and isospin chemical potentials. It is known that the homogeneous charged pion condensate emerges as a ground state at finite isospin chemical potential, and therein arises the Abrikosov vortex lattice with an applied magnetic field. We first demonstrate that a vortex with the same quantized magnetic flux as the conventional Abrikosov vortex, carries a baryon number captured by the third homotopy group of Skyrmions, once we take into account a modulation of the neutral pion inside the vortex core. Such a vortex-Skyrmion state is therefore dubbed the baryonic vortex. We further reveal that when the baryon chemical potential is above a critical value, the baryonic vortex has negative tension measured from the charged pion condensation. It implies that the phase, in which such vortices emerge spontaneously without an external magnetic field, would take over the ground state at high baryon density. Such a new phase contributes to the comprehension of QCD phase diagram and relates to the generation of magnetic fields inside neutron stars.
↳ hep-phhep-thnucl-thJHEP(2024)·15 citations
07
Investigating the soft and hard limits in transverse momentum spectra in pp collisions
Gábor Bíró🇭🇺 · Leonid Serkin🇲🇽 · Guy Paić🇲🇽 · Gergely Gábor Barnaföldi🇭🇺
The transverse momentum spectra and their multiplicity dependence serve as key tools for extracting parameters to be compared with theoretical models. Over the past decade, the scientific community has extensively studied the possibility of a system analogous to quark-gluon plasma, predicted in heavy nuclei collisions, also existing in collisions involving light nuclei and protons. We have reanalysed the data published by the ALICE Collaboration at the LHC. We present the dependence of the mean transverse momenta obtained in the soft and soft+hard (mixed) parts. Finally, we also discuss possible refinements of the analyses concerning the use of statistical parameters of higher order, aimed at a more detailed way of comparing the models with data.
↳ hep-phnucl-thEur.Phys.J.ST(2025)·6 citations
08
Holographic spin alignment for vector mesons
Xin-Li Sheng🇮🇹 · Yan-Qing Zhao🇨🇳 · Si-Wen Li🇨🇳 · Francesco Becattini🇮🇹 · Defu Hou🇨🇳
We develop a general framework for studying the spin alignment $ρ_{00}$ for flavorless vector mesons by using the gauge/gravity duality. Focusing on the dilepton production through vector meson decay, we derive the relation between production rates at each spin channel and meson's spectral function, which can be evaluated by holographic models for a strongly coupled system. As examples, we study $ρ_{00}$ for $J / ψ$ and $ϕ$ mesons, induced by the relative motion to a thermal background, within the soft-wall model. We show that $ρ_{00}$ in the helicity frame for $J / ψ$ and $ϕ$ mesons have positive and negative deviations from 1/3 at $T = 150$ MeV, respectively, which consequently leads to different properties for their global spin alignments.
↳ hep-phhep-thnucl-thPRD(2024)·30 citations
09
Using Equation of State Constraints to Classify Low-Mass Compact Binary Mergers
Jacob Golomb🇺🇸 · Isaac Legred🇺🇸 · Katerina Chatziioannou🇺🇸 · Adrian Abac🇩🇪 · Tim Dietrich🇩🇪
Compact objects observed via gravitational waves are classified as black holes or neutron stars primarily based on their inferred mass with respect to stellar evolution expectations. However, astrophysical expectations for the lowest mass range, $≲ 1.2 M_{⊙}$ , are uncertain. If such low-mass compact objects exist, ground-based gravitational wave detectors may observe them in binary mergers. Lacking astrophysical expectations for classifying such observations, we go beyond the mass and explore the role of tidal effects. We evaluate how combined mass and tidal inference can inform whether each binary component is a black hole or a neutron star based on consistency with the supranuclear-density equation of state. Low-mass neutron stars experience a large tidal deformation; its observational identification (or lack thereof) can therefore aid in determining the nature of the binary components. Using simulated data, we find that the presence of a sub-solar mass neutron star (black hole) can be established with odds $\sim 100 : 1$ when two neutron stars (black holes) merge and emit gravitational waves at signal-to-noise ratio $\sim 20$ . For the same systems, the absence of a black hole (neutron star) can be established with odds $\sim 10 : 1$ . For mixed neutron star-black hole binaries, we can establish that the system contains a neutron star with odds $≳ 5 : 1$ . Establishing the presence of a black hole in mixed neutron star-black hole binaries is more challenging, except for the case of a $≲ 1 M_{⊙}$ black hole with a $≳ 1 M_{⊙}$ neutron star companion. On the other hand, classifying each individual binary component suffers from an inherent labeling ambiguity.
↳ astro-ph.HEgr-qcnucl-thPRD(2024)·25 citations
10
Gapless neutron superfluidity can explain the late time cooling of transiently accreting neutron stars
Valentin Allard · Nicolas Chamel
The current interpretation of the observed late time cooling of transiently accreting neutron stars in low-mass X-ray binaries during quiescence requires the suppression of neutron superfluidity in their crust at variance with recent ab initio many-body calculations of dense matter. Focusing on the two emblematic sources KS~1731 $-$ 260 and MXB~1659 $-$ 29, we show that their thermal evolution can be naturally explained by considering the existence of a neutron superflow driven by the pinning of quantized vortices. Under such circumstances, we find that the neutron superfluid can be in a gapless state in which the specific heat is dramatically increased compared to that in the classical BCS state assumed so far, thus delaying the thermal relaxation of the crust. We have performed neutron-star cooling simulations taking into account gapless superfluidity and we have obtained excellent fits to the data thus reconciling astrophysical observations with microscopic theories. The imprint of gapless superfluidity on other observable phenomena is briefly discussed.
↳ astro-ph.HEcond-mat.supr-connucl-thPRL(2024)·12 citations
11
QCD Equation of State at nonzero baryon density in external magnetic field
N. Astrakhantsev🇨🇭 · V. V. Braguta🇷🇺 · A. Yu. Kotov🇷🇺 · A. A. Roenko🇷🇺
This paper is devoted to the study of QCD equation of state in external magnetic field and nonzero baryon density. Our study is carried out by means of lattice simulation with 2+1 dynamical staggered quarks at the physical masses. The simulation is conducted at imaginary baryon chemical potential what allowed us to overcome the sign problem. We expand the pressure in the baryon imaginary chemical potential and study three leading nonzero coefficients in this expansion. These coefficients were calculated for the following values of magnetic field: $e B = 0.3$ , $0.6$ , $1.2$ GeV $^{2}$ with the lattice sizes $8 \times 3 2^{3}$ , $10 \times 4 0^{3}$ , $12 \times 4 8^{3}$ . Using these data we take continuum limit for the coefficients. Our results indicate considerable enhancement of the expansion coefficients by the magnetic field.
↳ hep-lathep-phhep-thnucl-thPRD(2024)·24 citations
12
Probing new bosons and nuclear structure with ytterbium isotope shifts
Menno Door🇩🇪 · Chih-Han Yeh🇩🇪 · Matthias Heinz🇩🇪 · Fiona Kirk🇩🇪 · Chunhai Lyu🇩🇪 · Takayuki Miyagi🇩🇪 · Julian C. Berengut🇦🇺 · Jacek Bieroń🇵🇱 · Klaus Blaum🇩🇪 · Laura S. Dreissen🇩🇪 · Sergey Eliseev🇩🇪 · Pavel Filianin🇩🇪 and 15 other authors
In this Letter, we present mass-ratio measurements on highly charged Yb $^{42 +}$ ions with a precision of $4 \times 1 0^{- 12}$ and isotope-shift measurements on Yb $^{+}$ on the $^{2}$ S $_{1/2}$ $\to$ $^{2}$ D $_{5/2}$ and $^{2}$ S $_{1/2}$ $\to$ $^{2}$ F $_{7/2}$ transitions with a precision of $4 \times 1 0^{- 9}$ for the isotopes $^{168, 170, 172, 174, 176}$ Yb. We present a new method that allows us to extract higher-order changes in the nuclear charge distribution along the Yb isotope chain, benchmarking ab-initio nuclear structure calculations. Additionally, we perform a King plot analysis to set bounds on a fifth force in the keV $/ c^{2}$ to MeV $/ c^{2}$ range coupling to electrons and neutrons.
↳ physics.atom-phhep-phnucl-exnucl-thPRL(2025)·68 citations

Affiliations

first authorsco-authorsvia INSPIRE